High-frequency signaling system



July 22, 1930. i. F. BYRNES 1,771,376

HIGH FREQUENCY SIGNALING SYSTEM Fi1e c l March 31, 1927 ,2 Fig.

:1 -IHI- AA Al I v ls In verlbo'r-z Irving F. Barnes His Abporfig,

Patented July 22,

UNITED STATES ,PATENT OFFICE IRVING r. BYRNES, or SGHENECTADY, NEW YORK, ASSIGNOR 'ro GENERAL COMPANY, A conronarron on NEW YORK ELECTRIC V .HIGH-FREQUENGY SIGNALIN G SYS'LIEIIMII Application filed March 31,

My invention relates to high frequency signaling systems and more particularly to the transmitters of such systems in which electron discharge devices are employed. It has for its purpose to provide control means for electron discharge devices by means of which both the anode current and grid voltage may be simultaneously controlled in a positive and definite manner and in a manner such that sparking at the contacts of the control device is substantially eliminated. Ithas for its further purpose to so arrange the circuit that the contacts of the control device may be manually manipulated Without danger to the operator.

My invention has for its further purpose to provide means whereby both an'ampliiier and oscillator may be simultaneously controlled by a single control means thereby permitting moreefncient interruption of the operation of the system than'has heretofore been possible and without the provision of separate biasing means.

The novel features which I believe to be characteristic of my invention are set forth with particularity in the appended claims. My invention itself, however, both as to its organization and method of operation, together with further objects and advantages thereof will best be understood by reference to the following description taken in connection with the accompanying drawing in which rig. 1 represents my invention as applied to an oscillation generator and in which Fig. 2 illustrates my invention as applied to a master oscillator and power amplifier. WVith reference to Fig. 1, 1 illustrates an electron discharge device having an anode, cathode and a grid. The cathode of this electron discharge device is energized by means of a source of potential 2 and the anode is energized by means of a source of potential 3 through a circuit including the anode of the device 1, choke coil 4, source of potential 3, key 5, conductor 6 and the cathode of the electron, discharge device 1. The grid of the electron discharge device 1 is connected to the cathode through a circuit including the conductor 7, grid leak resistance 8, key 5, conductor 6 back to the cathode of the device 1.

1927. Serial N0.179,9G2.

The oscillatory circuit of the generator comprises a circuit leading from the anode of the device 1 through the condenser 9, primary winding ofthe output transformer 10, condenser 11, conductor 7' and grid of the device 1. The secondary winding of the transformer 10 is connected in circuit with the antenna 12. Anintermediate point on the primary winding of the transformer 10 is connected through a conductor 61to the cathode of the device 1. Since the generator described is of a well-known type, further description of its operation will not be set forth.

It will be noted that the key 5 is inserted in a connection which is common to the circuit leading froin tl1egrid of the device 1 to the cathode and the circuit leading from the anode of the device 1 through the source of potential 3 to the cathode. In parallel with the key 5 is connected a parallel combination of capacitance 13 and resistance 14. Inthe operation of my device when the he '5 is'closed the circuit is made from both the anode and grid of the device 1 through the tween the anode and cathode'of the device 1 and the space between the. movable contact and stationary; contact of the key. 5 are both connected in series across the source of potential 3 through a circuit which has heretofore been traced as the anode circuit of the device 1. Due to the fact that the impedance be tween the cathode and the anode of the device 1 is of somewhat smaller value than that be tween the contacts of the key 5 practically the whole potential of the source 3 will, unless further means are provided, distribute itself across the contacts of the key 5, and hence across the space between the grid and cathode of the device 1. This being the case the key charge of condenser 13' but which will pass current sufiicient to cause the voltage of the source 3 to distribute itself between the anode and cathode of the device 1 thereby permitting manual operation of the key 5.

In Fig. 2 I have showna signaling system employing both an oscillator and amplifier which are controlled in accordance with my inventlon. 15. represents an electron discharge devlce which is employed as an oscillation generator and 16 represents electron discharge devices which are connected in parallel for operation as amplifiers of the oscillations produced by the generator 15.

K The cathodes of each of these electron discharge devices are connected through cathode conductors 17 to the secondary winding of the cathode transformer 18, the primary of which is energized from any suitable source of potential. The oscillation generator is provided with the usual oscillatory circuit 20 which is made up of a parallel com bination of inductance and capacity one extremity of which is connected through a condenser 21 to the anode of the device 15 and the other extremity of which is connected through a conductor 22 to the grid of the device 15. Oscillatory currents from the oscillatory circuit 20 are impressed upon the grids of the amplifiers 16 through a circuit including the coupling condenser 23, resistance 24, conductor 25, and conductors 26 to the grid of the amplifiers 16.

The grid circuit of the device 15 is connected through the conductor 22, grid leak resistance 27, conductor 28, conductor 29, key 30, conductor 31, and conductor 32 which is connected to the midpoint of the secondary winding of the cathode transformer 18. The grid circuit of the amplifiers 16 are connected through conductor 26, conductor 25,

choke coil 33, resistance 34, conductor 29, key

30, conductor 31 and conductor 32 to the midpoint of the secondary winding of the cathode transformer 18,. The anode circuit of the oscillation generator 15 is connected through a'choke coil 89, conductor 40, source of potential 38, conductor 29, key 30, conductor 31, conductor 32 to the midpoint of the sec- 'ondary winding of the transformer 18, and

likewise the anode circuit of the amplifier 16 comprises the conductor 35, primary winding of the output transformer 36, conductor 37, source of potential'38, conductor 29, key 30, conductor 31, conductor 32 to the midpoint of the secondary winding of the transformer 18. It will thus be seen that the key 30 is inserted in both the anode circuit and the grid leak circuit of each of the electron discharge devices of the system and that the flow of current in all of these anode circuits is simultaneously interrupted by operation of the key. In parallel with the key are connected the resistance i1 and condenser 4-2. vVhen the key is closed ,the'grids of the various devices will be substantially at the voltage of the cathodes and the system will be operative, oscillations being produced by the oscillationv generator 15 and amplified by the amplifier 16 and thence transmitted tothe antenna 43 through the output transformer 36 When the key is open a voltage will build up across the condenser {12 and resistance 41 thereby' mpressing a strong negative potential upon the grids of both the.

oscillator and power amplifier thereby effectively interrupting any operation of the sys tem. As has been explained in connection with Fig. 1, were it not for the resistance 41 when the key is opened the space between the contacts of the key 30 and'the space be tween the cathodes and anodes of the va rious discharge devices. would be connected in series across the'source of potential 38 and'consequently due to the fact: that the impedance at the key is greater than that of the electron discharge devices practically the entire anode voltage will distribute itself across the key 30; By insertingth e resistance 11 in parallelwith the key 30 a very small current is permitted to flow through the electron discharge devices and this will be sufiicient to cause the voltage of the source 38 to distribute itself between the cathode and the anodes of the oscillation generator 15 a.

and amplifiers 1,6. This current through re sistance etl is so small that the electron discharge devices cannot operate. In consequence the key 30 may be manipulated by the operator without sparking and without danger from excessive voltages. It may thus be seen that the operation of both the oscillation generator and that of the amplifier is effectively interrupted by means of the key 30 without excessive sparking at the key and without danger of injury to the operator, the voltage across the key and hence the grid voltage being positively controlled by the condenser 12 and resistance 41. The condenser M is permanently connected in parallel with the source of potential 38 for the purpose of bypassing high frequency currents. Thus it will be noted that this condenser is always in a charged state and hence no charging current is keyed bythe device 30.

WhileI have shown and described the preferred embodiment of my invention it will be apparent that the invention is not limited to the particular embodiment shown but that many modifications may be made in the circuit arrangement and the instrumentalities employed without departing from the scope thereof as set forth in the appended claims.

What I claim as new and desire to secure. by Letters Patent of the United States, is:

1. In a high frequency signaling system employed an electron discharge device having an anode, a cathode and a grid, a source of potential for said anode, a resistance permanently connected between said grid and the negative side of said source of potential, a connection between said cathode and the negative side of said source of potential, means for controlling the operation of said electron discharge device comprising a contact making key inserted in said last men tioned connection, one side of said key being connected both to the negative side of said source of potential and to said grid, and the other side of said key being connected to the cathode, and a parallel combination of resistance and capacitance connected in parallel with said key.

2. In a high frequency signaling system employing electron discharge devices each of said devices having an anode, a cathode and a grid, a source of potential for said anodes, a permanent connection between said grids and the negative side of said source of potential, a connection between said cathodes and the negative side of said source of potential, means for controlling the operation of said signaling system comprising a contact making key inserted in said last mentioned connection, one side of said key being connected to the negative side of said source of potentialand to said grid, and the other side of said key being connected to the cathode, and means associated therewith and adapted to maintain a definite negative potential on said grids and across said key when said key is open, said means comprising a parallel combination of capacitance and resistance connected in parallel with said key.

3. In a high frequency signaling system employing a master oscillator and power amplifier for oscillations produced by said oscillator, said oscillator and said amplifier being of the vacuum tube type, a source of potential for the anodes of said oscillator and said amplifier, a permanent connection between the grids of said oscillator and said amplifier and the negative side of said source of potential, a connection between the oathodes of said oscillator and said amplifier and the negative side of said source of potential, means for controlling the operation of said oscillator and said amplifier comprising a contact making key inserted in said last mentioned connection, one side of said key being connected to the negative side of said source of potential and to said grid, and the other connected to the oathode, and means associated therewith and 

